Concern with negative consequences of drug education centers around intended outcomes, outcome priorities, observed outcomes, balance of positive versus negative outcomes, and nature of the evidence supporting conclusions about outcomes. Views differ concerning the acceptability of alternative forms of evidence in assessing the impact of drug education. Much of the data from non-experimental studies is based on single surveys that provide observations at a single point in time. Further, non-experimental research has been expository rather than exhaustive. In the area of experimental evidence, relatively few scientifically conducted studies have demonstrated negative effects of drug education programs. Most reported negative findings have involved a significant increase in reported drug use among those receiving experimental drug education programs, and few studies in which negative findings have been reported have been free of major design problems. Both non-experimental and experimental evidence shows negative drug education program effects are not isolated phenomena and occur frequently enough and affect self-reported behavior often enough to require more careful scrutiny. Further research is required that involves greater clarity and rigor in the conceptualization, development, implementation, and evaluation of drug education programs; greater emphasis on increased understanding of the dynamics of successful drug education programs; greater emphasis on the scientific quality of drug education research and on the investigation of alternative drug education program modalities; and greater attention to the timing of drug education and to the mediating role of teachers in implementing drug education programs. 30 references